1. Add vegetable broth to a medium saucepan, along with saffron and salt. Heat mixture until saffron dissolves. In a pot, add oil and heat. Add rice and toast for about 3 minutes. Pour in half of the warm broth and stir to combine. Simmer rice until most of the broth has been absorbed. Add broth 1 cup at a time until absorbed, stirring rice every few minutes to prevent burning. Continue this process until rice is al dente and sticking together. Remove from heat and cool down in an ice bath. Stir in margarine and Parmigiano Reggiano. Cool rice in the fridge for about 3 hours.
2. Add margarine to a pan and heat until melted. Stir in flour and cook for a few minutes. Add soy milk and stir until slightly thickened. Add peas, squash, and mozzarella. Mix well.
3. Add flour to a deep bowl and season with salt and pepper. Add water and whisk until smooth. Reserve.
4. Using an ice cream scoop, make tennis ball-size portions of the chilled risotto and shape into cones. Place on a tray. Allow molded rice to rest for 30 minutes to set. Make a hole in each rice ball, carefully pushing downward to enlarge the hole. Place back onto the tray.
5. Fill the hole with prepared filling. Close the hole by pushing filling down and rice over it. Now roll the filled arancini in your hands shaping it and smoothing any cracks or holes. Continue to shape into a cone. Place each on tray and reserve.
6. Pour breadcrumbs into a bowl. Whisk batter. Immerse each filled rice ball into the batter one at a time and then coat it in the breadcrumbs. Reserve on parchment lined pan. Heat oil to about 350°F. Add arancini into pot and fry for 2 to 3 minutes until golden brown. Once cooked, place onto paper towel to drain. Serve immediately